Preparation method of coal gas desulfurizer with high desulfurization-regeneration performance

Abstract

The application discloses a preparation method of a high desulfurization-regeneration performance coal gas desulfurizer, and belongs to the technical field of coal chemical industry desulfurizer preparation. The preparation method comprises the following steps: sequentially immersing a silica nanofiber aerogel carrier in a mixed solution of zinc nitrate and cobalt nitrate, a NaNO3 solution, a NaF solution and a NaCl solution for treatment to obtain a desulfurizer precursor; and performing microwave low-temperature calcination on the desulfurizer precursor to generate active components ZnCo2O4 in the silica nanofiber aerogel carrier, so as to obtain the high desulfurization-regeneration performance coal gas desulfurizer. The preparation process route of the desulfurizer is simple and easy to implement, the prepared desulfurizer has excellent regeneration performance, the regeneration temperature is low, and the performance requirements of desulfurizer industrialization can be met; on the other hand, the flexible and high-porosity fiber material is used as the carrier to construct the multi-level micro-pore structure of the desulfurizer, so that the adsorption capacity and desulfurization reaction activity of the desulfurizer can be improved.

Description

Technical Field

[0001] This invention relates to the field of coal chemical desulfurization agent preparation technology, and in particular to a method for preparing a coal gas desulfurization agent with high desulfurization-regeneration performance. Background Technology

[0002] As one of the three major fossil fuels, coal's fundamental energy importance in economic development is unshakeable. However, the various environmental problems caused by the direct combustion of coal cannot be ignored. Integrated gasification combined cycle (IGCC) power generation technology, based on the clean and efficient utilization of coal, has been widely adopted in many countries and regions. Coal gas, as the power and feedstock source in IGCC technology, contains a large amount of sulfides, more than 90% of which is hydrogen sulfide (H2S). Hydrogen sulfide not only corrodes industrial equipment and poisons catalysts, but also poses a threat to the ecological environment and human health when released into the atmosphere. Therefore, hydrogen sulfide must be completely removed from coal gas before use.

[0003] Dry desulfurization utilizes metal oxides in solid-phase desulfurizing agents to convert and remove H2S through chemical reactions. This method has advantages such as simple process flow, no wastewater or waste acid treatment issues, low energy consumption, low equipment corrosivity, and low cost. Studies have shown that desulfurizing agents with zinc oxide as the active component have higher desulfurization precision and efficiency than other oxide desulfurizing agents. However, zinc oxide is prone to volatilization during high-temperature regeneration, leading to loss of active components and severe performance degradation. Copper oxide has a strong affinity and adsorption capacity for hydrogen sulfide. Some researchers have found that copper oxide desulfurizing agents have high desulfurization precision, are less affected by temperature, and have good regeneration performance.

[0004] However, current dry desulfurization technologies suffer from drawbacks such as large desulfurizing agent loading, frequent agent replacement, difficulty in regenerating spent desulfurizing agents, and challenges in solid waste treatment. While existing desulfurizing agent preparation methods and regeneration processes are relatively mature, they still suffer from drawbacks such as high regeneration temperatures, difficulty in regeneration leading to short service life, and high operating costs. Therefore, existing desulfurizing agents cannot meet the requirements of practical industrial applications, and developing novel, highly efficient, and regenerable solid desulfurizing agents with high desulfurization efficiency, speed, and selectivity remains one of the goals of gas desulfurization technology. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a coal gas desulfurizer with high desulfurization-regeneration performance, so as to solve the problems of low utilization rate of active components and poor sulfidation-regeneration performance of desulfurizer during the reaction process, and ultimately improve the sulfidation and recycling performance of desulfurizer.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] One of the technical solutions of the present invention is a method for preparing a high-desulfurization-regeneration performance coal gas desulfurizer, comprising the following steps: immersing a silica nanofiber aerogel carrier sequentially in a mixed solution of zinc nitrate and cobalt nitrate, a NaNO3 solution, a NaF solution, and a NaCl solution to obtain a desulfurizer precursor; subjecting the desulfurizer precursor to low-temperature calcination to generate the active component ZnCo2O4 in the silica nanofiber aerogel carrier, thereby obtaining the high-desulfurization-regeneration performance coal gas desulfurizer.

[0008] Furthermore, the porosity of the silica nanofiber aerogel carrier is 95-99.99%, and the diameter of the silica nanofibers is 100-1000 nm.

[0009] Furthermore, in the mixed solution of zinc nitrate and ferric nitrate, the molar ratio of zinc nitrate to ferric nitrate is 1:2, and the concentration of zinc nitrate is 0.1 mol / L.

[0010] Furthermore, the concentrations of the NaNO3 solution, NaF solution, and NaCl solution are all 5-8 mmol / L.

[0011] Furthermore, during the soaking treatment, the volume ratio of the silica nanofiber aerogel carrier to the mixed solution of zinc nitrate and cobalt nitrate, NaNO3 solution, NaF solution, and NaCl solution is 1:1; and the soaking time is 24 hours.

[0012] The sequential immersion of the silica nanofiber aerogel carrier in a mixed solution of zinc nitrate and cobalt nitrate, NaNO3 solution, NaF solution, and NaCl solution constitutes an equal-volume impregnation process between the aerogel solid and liquid components, allowing the carrier to completely absorb the impregnation solution. The sequential immersion in NaNO3, NaF, and NaCl solutions, rather than in a mixed solution of NaNO3, NaF, and NaCl, is to avoid competition between different ions, thereby improving the impregnation loading effect and ensuring that all ions are impregnated and loaded onto the carrier.

[0013] Furthermore, the specific parameters for the low-temperature calcination include: an oxygen concentration of 1-4 vol%, a microwave power of 1500-3000 W, a calcination temperature of 250-400℃, and a calcination time of 2 h.

[0014] The second technical solution of the present invention: a high desulfurization-regeneration performance coal gas desulfurizer prepared by the above preparation method.

[0015] Furthermore, the high desulfurization-regeneration performance coal gas desulfurizer uses silica nanofiber aerogel as a carrier, and the carrier is loaded with the active component ZnCo2O4, which can be called ZnCo2O4 / silica nanofiber aerogel composite desulfurizer.

[0016] Furthermore, the ZnCo2O4 content in the high desulfurization-regeneration performance coal gas desulfurizer is 57.5 wt%.

[0017] The third technical solution of the present invention: a regeneration method for the above-mentioned high desulfurization-regeneration performance coal gas desulfurizer, comprising the following steps: using a mixed gas with an oxygen concentration of 2 vol%, at a temperature of 450°C for 2000 h. -1 The high-performance desulfurization-regeneration coal gas desulfurizer after desulfurization reaction is regenerated at a space velocity of 0.5 to obtain the regenerated coal gas desulfurizer.

[0018] Furthermore, the mixed gas is a mixture of oxygen and nitrogen (i.e., nitrogen is used as the balance gas), which can be expressed as 2 vol% oxygen + 98 vol% nitrogen.

[0019] Furthermore, the specific operation of the desulfurization reaction is as follows: a high-performance desulfurization-regeneration gas desulfurizer is placed in a fixed-bed reactor and reacted at a rate of 2000 h⁻¹. -1 Gas is introduced at air velocity and desulfurization reaction is carried out at 500℃.

[0020] The present invention discloses the following technical effects:

[0021] This invention uses silica nanofiber aerogel as a carrier, and then prepares a ZnCo2O4 / silica nanofiber aerogel composite desulfurizer through methods such as metal salt solution impregnation and low-temperature calcination. It has the following advantages:

[0022] (1) This invention uses silica nanofiber aerogel as a carrier to prepare desulfurizer. It utilizes the open pore structure, high flexibility and stable physical structure of nanofiber aerogel, and combines the excellent wear resistance and heat resistance of silica nanofiber. While providing support for the overall structure of the desulfurizer, the stable physical structure and rich pore structure of nanofiber aerogel can promote the adsorption and reaction process of desulfurizer and maintain the long-term cyclic use performance of desulfurizer.

[0023] (2) The process steps of the present invention are simple, highly controllable, and easy to operate, which can meet the large market demand. The silica nanofiber aerogel has good support, high flexibility, high toughness and strength, high porosity and large specific surface area, and can realize multi-component composite and multi-level structure synergy.

[0024] (3) More importantly, this invention combines zinc and cobalt, which not only forms a composite oxide, improving the stability of zinc and the regeneration performance of the desulfurizer, but also reduces the stability of the composite oxide's lattice structure based on the size difference between zinc and cobalt ions. Furthermore, by utilizing the lattice diffusion of zinc and cobalt ions during low-temperature calcination, the migration of alkali metal sodium, the generation of oxygen vacancies by non-metallic fluorine and chlorine, and the promoting effect of microwave radiation on metal ion migration, a significant Kirkendall effect is generated. This leads to a large number of lattice defects (metal ion defects and oxygen vacancies) in the zinc-cobalt composite oxide, and even transforms it into a hollow structure (such as...). Figure 1 and Figure 2 As shown); based on this, after the desulfurization reaction, due to the substitution process of sulfur ions and oxygen ions, but the diffusion rates of these two ions are different, the Kirkendall effect of metal ions still exists, and a large number of lattice defects (metal ion defects and sulfur vacancies, such as...) will still be generated. Figure 3 (As shown). Taking the oxygen regeneration process of the desulfurizer as an example, the presence of lattice defects in the sulfide products not only facilitates the adsorption and dissociation of oxygen, but also helps to weaken the chemical bonds between metal and sulfur, reduce the activation energy of bond breaking, and thus lower the regeneration reaction temperature. This allows the desulfurizer to avoid the adverse effects of high-temperature sintering, maintain a high gas-solid reaction rate and mass transfer efficiency, and improve the recyclability of the desulfurizer. Tests show that the desulfurizer prepared by the method of this invention not only achieves a single-use active component utilization rate of 95.77%, but also achieves a regeneration rate of 97% even when the regeneration reaction temperature is reduced to 450℃. After ten sulfide-regeneration cycles, the active component utilization rate is still 92.53%. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 The image shows the HRTEM characterization of the desulfurizer prepared in Example 1, where a, b, and c represent TEM images at different magnifications, d is the lattice analysis of the composite metal oxide in the desulfurizer, e is the morphology image of the desulfurizer, and fj is the elemental distribution map of the desulfurizer.

[0027] Figure 2 EPR characterization diagrams of the desulfurizing agents prepared in Example 1 and Comparative Example 1;

[0028] Figure 3The images shown are HRTEM characterization images of the desulfurizing agent prepared in Example 1 after the desulfurization reaction. In the images, a, b, and c represent TEM images at different magnifications, d and e are lattice analyses of the composite metal oxide after the desulfurization reaction, f is a morphology image of the desulfurizing agent, and g and k are elemental distribution diagrams. Detailed Implementation

[0029] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0030] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0032] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0033] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0034] In the following examples and comparative examples, room temperature or ambient temperature specifically refers to 20-25°C.

[0035] The silica nanofiber aerogel carriers used in the following examples and comparative examples have a porosity of 99%, and the average diameter of the silica nanofibers is 500 nm. Silica nanofiber aerogel carriers are commercially available or can be prepared using conventional methods, such as airflow-assisted electrospinning, nanofiber remodeling, and freeze-drying to prepare silica nanofiber aerogels from SiO2. Specific preparation details are not limited, as long as the requirements for porosity and average nanofiber diameter are met. Specific preparation details do not affect the technical effectiveness of this solution.

[0036] The testing and calculation methods for sulfur capacity, active component utilization rate, and desulfurizer regeneration rate in the following examples and comparative examples are as follows:

[0037] The desulfurization performance of the samples was evaluated using breakthrough sulfur capacity as the indicator. The H2S concentration in the inlet gas was 1000 ppm. When the H2S concentration in the outlet gas reached 300 ppm, it was considered that the desulfurizing agent had broken through; the time taken for this to occur was considered the breakthrough time. Breakthrough sulfur capacity is converted into the mass (g) of elemental sulfur absorbed by 100g of desulfurizing agent from the start of the experiment until the breakthrough time. The detailed calculation method is as follows:

[0038]

[0039] Where: F is the flow rate of the simulated gas (mL / min), M s The molar mass of S is 32.06 g / mol, and the molar mass of V is V. m The molar volume of the gas at 25℃ and 101.325 kPa is 24.5 L / mol; C0 and C represent the inlet and outlet concentrations of H2S (ppm), respectively; M 脱硫剂 Corresponding to the mass (g) of the desulfurizing agent.

[0040] Utilization rate of active components = actual sulfur capacity / theoretical sulfur capacity × 100%.

[0041] Regeneration rate = (mass of desulfurizer lost during regeneration / mass of desulfurizer increased during desulfurization reaction) × 100%.

[0042] Example 1

[0043] A method for preparing a high-performance desulfurization-regeneration coal gas desulfurizer, comprising the following steps:

[0044] (1) Metal ion impregnation: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 5.82 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.02 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as the impregnation solution; the silica nanofiber aerogel carrier was immersed in the impregnation solution in an equal volume at room temperature for 24 h (by volume ratio, silica nanofiber aerogel: impregnation solution = 1:1), and the water was air-dried after the immersion treatment;

[0045] (2) Preparation of desulfurizing agent precursor: The silica nanofiber aerogel carrier after soaking in step (1) was soaked in equal volumes of 5 mmol / L NaNO3 solution, NaF solution and NaCl solution at room temperature for 24 h. After each soaking treatment, the water was dried to obtain the desulfurizing agent precursor.

[0046] (3) Preparation of high desulfurization-regeneration performance coal gas desulfurizer: The desulfurizer precursor obtained in step (2) was subjected to microwave low-temperature calcination in a mixed gas (1 vol% oxygen + 99 vol% nitrogen) with an oxygen concentration of 1 vol% and a microwave power of 1500 W. The low-temperature calcination temperature was 250℃ and the calcination time was 2 h. The active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier, and the high desulfurization-regeneration performance coal gas desulfurizer (the ZnCo2O4 content in the desulfurizer was 57.5 wt%) was obtained.

[0047] The desulfurizing agent (0.1 g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1 Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0048] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 26.39%, and the utilization rate of the active component was 93.90%.

[0049] Subsequently, a mixed gas with an oxygen volume concentration of 2 vol% (2 vol% oxygen + 98 vol% nitrogen) was used at a temperature of 450°C and a space velocity of 2000 h⁻¹. -1 The desulfurizing agent is then regenerated for 3 hours to obtain regenerated desulfurizing agent, which is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is completed, regeneration is performed again under the same conditions.

[0050] After ten cycles of sulfidation / regeneration, the desulfurizer showed a regeneration rate of 90%, a sulfur capacity of 22.78%, and an active component utilization rate of 81.07%.

[0051] Example 2

[0052] A method for preparing a high-performance desulfurization-regeneration coal gas desulfurizer, comprising the following steps:

[0053] (1) Metal ion impregnation: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 5.82 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.02 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as the impregnation solution; the silica nanofiber aerogel carrier was immersed in the impregnation solution in an equal volume at room temperature for 24 h (by volume ratio, silica nanofiber aerogel: impregnation solution = 1:1), and the water was air-dried after the immersion treatment;

[0054] (2) Preparation of desulfurizing agent precursor: The silica nanofiber aerogel carrier after soaking in step (1) was soaked in equal volumes of 6 mmol / L NaNO3 solution, NaF solution and NaCl solution at room temperature for 24 h. After each soaking treatment, the water was dried to obtain the desulfurizing agent precursor.

[0055] (3) Preparation of high desulfurization-regeneration performance coal gas desulfurizer: The desulfurizer precursor obtained in step (2) was subjected to microwave low-temperature calcination in a mixed gas (2 vol% oxygen + 98 vol% nitrogen) with a microwave power of 2000W. The low-temperature calcination temperature was 300℃ and the calcination time was 2h. The active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier, and the high desulfurization-regeneration performance coal gas desulfurizer (the content of ZnCo2O4 in the desulfurizer was 57.5wt%) was obtained.

[0056] The desulfurizing agent (0.1 g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1 Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0057] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 26.68%, and the utilization rate of the active component was 94.95%.

[0058] Subsequently, a mixed gas with an oxygen volume concentration of 2 vol% (2 vol% oxygen + 98 vol% nitrogen) was used at a temperature of 450°C and a space velocity of 2000 h⁻¹. -1 The desulfurizing agent is then regenerated for 3 hours to obtain regenerated desulfurizing agent, which is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is completed, regeneration is performed again under the same conditions.

[0059] After ten cycles of sulfidation / regeneration, the desulfurizer showed a regeneration rate of 93%, a sulfur capacity of 24.39%, and an active component utilization rate of 86.80%.

[0060] Example 3

[0061] A method for preparing a highly efficient regenerable coal gas desulfurizing agent, comprising the following steps:

[0062] (1) Metal ion impregnation: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 5.82 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.02 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as the impregnation solution; the silica nanofiber aerogel carrier was immersed in the impregnation solution in an equal volume at room temperature for 24 h (by volume ratio, silica nanofiber aerogel: impregnation solution = 1:1), and the water was air-dried after the immersion treatment;

[0063] (2) Preparation of desulfurizing agent precursor: The silica nanofiber aerogel carrier after soaking in step (1) was soaked in equal volumes of 7 mmol / L NaNO3 solution, NaF solution and NaCl solution at room temperature for 24 h. After each soaking treatment, the water was dried to obtain the desulfurizing agent precursor.

[0064] (3) Preparation of high desulfurization-regeneration performance coal gas desulfurizer: The desulfurizer precursor obtained in step (2) was subjected to microwave low-temperature calcination in a mixed gas (3 vol% oxygen + 97 vol% nitrogen) with an oxygen concentration of 3 vol% and a microwave power of 2500 W. The low-temperature calcination temperature was 350℃ and the calcination time was 2 h. The active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier, and the high desulfurization-regeneration performance coal gas desulfurizer (the ZnCo2O4 content in the desulfurizer was 57.5 wt%) was obtained.

[0065] The desulfurizing agent (0.1 g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1 Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0066] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 26.91%, and the utilization rate of the active component was 95.77%.

[0067] Subsequently, a mixed gas with an oxygen volume concentration of 2 vol% (2 vol% oxygen + 98 vol% nitrogen) was used at a temperature of 450°C and a space velocity of 2000 h⁻¹. -1Next, the desulfurizing agent is regenerated to obtain regenerated desulfurizing agent, which is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is completed, regeneration is performed again under the same conditions.

[0068] After ten cycles of sulfidation / regeneration, the desulfurizer showed a regeneration rate of 97%, a sulfur capacity of 26.00%, and an active component utilization rate of 92.53%.

[0069] Example 4

[0070] A method for preparing a high-performance desulfurization-regeneration coal gas desulfurizer, comprising the following steps:

[0071] (1) Metal ion impregnation: 2.97 g of zinc nitrate (specifically Zn(NO3)2·6H2O, 0.01 mol) and 5.82 g of cobalt nitrate (specifically Co(NO3)2·6H2O, 0.02 mol) precursors of the active component ZnCo2O4 were dissolved in 100 mL of water to obtain a mixed solution of zinc nitrate and cobalt nitrate as the impregnation solution; the silica nanofiber aerogel carrier was immersed in the impregnation solution in an equal volume at room temperature for 24 h (by volume ratio, silica nanofiber aerogel: impregnation solution = 1:1), and the water was air-dried after the immersion treatment;

[0072] (2) Preparation of desulfurizing agent precursor: The silica nanofiber aerogel carrier after soaking in step (1) was soaked in equal volumes of 8 mmol / L NaNO3 solution, NaF solution and NaCl solution at room temperature for 24 h. After each soaking treatment, the water was dried to obtain the desulfurizing agent precursor.

[0073] (3) Preparation of high desulfurization-regeneration performance coal gas desulfurizer: The desulfurizer precursor obtained in step (2) was subjected to microwave low-temperature calcination in a mixed gas (4 vol% oxygen + 96 vol% nitrogen) with an oxygen concentration of 4 vol% and a microwave power of 3000 W. The low-temperature calcination temperature was 400℃ and the calcination time was 2 h. The active component ZnCo2O4 was generated in the silica nanofiber aerogel carrier, and the high desulfurization-regeneration performance coal gas desulfurizer (the ZnCo2O4 content in the desulfurizer was 57.5 wt%) was obtained.

[0074] The desulfurizing agent (0.1 g) prepared in this embodiment was placed in a fixed-bed reactor and reacted at a space velocity of 2000 h⁻¹. -1 Texaco simulated coal gas is introduced and a desulfurization reaction is carried out at 500°C until absorption saturation.

[0075] After the desulfurization reaction was completed, the sulfur capacity of the desulfurizing agent was found to be 25.99%, and the utilization rate of the active component was 92.49%.

[0076] Subsequently, a mixed gas with an oxygen volume concentration of 2 vol% (2 vol% oxygen + 98 vol% nitrogen) was used at a temperature of 450°C and a space velocity of 2000 h⁻¹. -1 The desulfurizing agent is then regenerated for 3 hours to obtain regenerated desulfurizing agent, which is then used in the desulfurization reaction of Texaco simulated coal gas under the same conditions. After the desulfurization reaction is completed, regeneration is performed again under the same conditions.

[0077] After ten cycles of sulfidation / regeneration, the desulfurizer showed a regeneration rate of 88%, a sulfur capacity of 21.93%, and an active component utilization rate of 78.04%.

[0078] Comparative Example 1

[0079] Commercially available ZnCo2O4 was used as the active component, and a desulfurizing agent was prepared by mechanically mixing ZnCo2O4 and silica nanofiber aerogel at a certain mass ratio (57.5:42.5).

[0080] The specific operation of mechanical mixing is as follows: ZnCo2O4 is dispersed in water to prepare a ZnCo2O4 dispersion with a concentration of 0.1 mol / L. Silica nanofiber aerogel is added, and after mechanical stirring for 3 hours, the silica nanofiber aerogel is taken out and dried to obtain a desulfurizing agent (the ZnCo2O4 content in the desulfurizing agent is 57.5 wt%).

[0081] Under the same desulfurization reaction experimental conditions as in Example 1, the initial sulfur capacity of the mechanically mixed ZnCo2O4 / silica nanofiber aerogel desulfurizer prepared in this comparative example was tested to be 11.3%, and the utilization rate of the active component was 40.21%.

[0082] After desulfurization, regeneration was carried out under the same conditions as in Example 1. After ten sulfidation / regeneration cycles, the regeneration rate of the mechanically mixed ZnCo2O4 / silica nanofiber aerogel desulfurizer was 60.1%, the sulfur capacity decreased to 6.1%, and the utilization rate of the active component was 21.71%.

[0083] Comparative Example 2

[0084] Same as Example 1, except that the operation in step (2) is as follows: the silica nanofiber aerogel carrier after soaking in step (1) is soaked in equal volumes of 5 mmol / L NaNO3 solution and NaCl solution for 24 h to obtain the desulfurizing agent precursor.

[0085] Under the same desulfurization reaction experimental conditions as in Example 1, the initial sulfur capacity of the desulfurizer prepared in this comparative example was tested to be 24.83%, and the utilization rate of the active component was 88.36%.

[0086] After desulfurization, regeneration was carried out under the same conditions as in Example 1. After ten sulfidation / regeneration cycles, the regeneration rate of the desulfurizing agent was 83%, the sulfur capacity decreased to 22.19%, and the utilization rate of the active component was 78.97%.

[0087] Comparative Example 3

[0088] Same as Example 1, except that the operation in step (2) is as follows: the silica nanofiber aerogel carrier after the impregnation treatment in step (1) is soaked in equal volumes of 5 mmol / L NaF solution and NaCl solution for 24 h to obtain the desulfurizing agent precursor.

[0089] Under the same desulfurization reaction experimental conditions as in Example 1, the initial sulfur capacity of the desulfurizer prepared in this comparative example was tested to be 24.61%, and the utilization rate of the active component was 87.58%.

[0090] After desulfurization, regeneration was carried out under the same conditions as in Example 1. After ten sulfidation / regeneration cycles, the regeneration rate of the desulfurizing agent was 84%, the sulfur capacity decreased to 21.01%, and the utilization rate of the active component was 74.77%.

[0091] Comparative Example 4

[0092] Same as Example 1, except that in step (3), the roasting heating method is changed to a conventional non-microwave heating method. The low-temperature roasting temperature is 300℃ and the roasting time is 2h.

[0093] Under the same desulfurization reaction experimental conditions as in Example 1, the initial sulfur capacity of the desulfurizer prepared in this comparative example was tested to be 18.78%, and the utilization rate of the active component was 66.83%.

[0094] After desulfurization, regeneration was carried out under the same conditions as in Example 1. After ten sulfidation / regeneration cycles, the regeneration rate of the desulfurizing agent was 80.8%, the sulfur capacity decreased to 13.57%, and the utilization rate of the active component was 48.29%.

[0095] Test Example 1

[0096] The desulfurizing agent prepared in Example 1 was characterized by HRTEM, and its HRTEM characterization pattern is shown below. Figure 1 As shown, a, b, and c (the circled part in c represents metal ion defects) represent TEM images at different magnifications, d is the lattice analysis of the composite metal oxide in the desulfurizing agent, e is the morphology image of the desulfurizing agent, and fj is the elemental distribution map of the desulfurizing agent. Figure 1 It can be seen that the desulfurizing agent contains a large number of metal ion vacancies, and the elements Si, N, O, Zn and Co are evenly distributed, which proves the successful synthesis of ZnCo2O4.

[0097] The desulfurizing agent prepared in Example 1 and the desulfurizing agent prepared in Comparative Example 1 were subjected to EPR characterization. The EPR characterization diagrams of the two are shown below. Figure 2 As shown in the EPR characterization diagram, the oxygen vacancy concentration of the two is compared. It can be seen from the EPR characterization diagram that the desulfurizer prepared in Example 1 contains a large number of oxygen vacancies.

[0098] After the desulfurizing agent prepared in Example 1 underwent one desulfurization reaction, it was characterized again by HRTEM. The TEM characterization image of the desulfurizing agent after the desulfurization reaction is shown below. Figure 3 As shown, a, b, and c (the circled part in c represents metal ion defects) represent TEM images at different magnifications; d and e are lattice analyses of the composite metal oxide after the desulfurization reaction; f is the morphology of the desulfurizing agent; and g and k are elemental distribution diagrams. Figure 3 It can be seen that the desulfurizing agent still contains a large number of metal ion vacancies after the desulfurization reaction.

[0099] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a high-performance desulfurization-regeneration coal gas desulfurizer, characterized in that, Includes the following steps: The silica nanofiber aerogel carrier was sequentially immersed in a mixed solution of zinc nitrate and cobalt nitrate, a NaNO3 solution, a NaF solution, and a NaCl solution to obtain a desulfurizing agent precursor. The desulfurizing agent precursor was then subjected to microwave low-temperature calcination to generate the active component ZnCo2O4 in the silica nanofiber aerogel carrier, thus obtaining the high desulfurization-regeneration performance coal gas desulfurizing agent.

2. The preparation method according to claim 1, characterized in that, The porosity of the silica nanofiber aerogel carrier is 95-99.99%, and the diameter of the silica nanofibers is 100-1000 nm.

3. The preparation method according to claim 1, characterized in that, The molar ratio of zinc nitrate to cobalt nitrate in the mixed solution of zinc nitrate and cobalt nitrate is 1:2, and the concentration of zinc nitrate is 0.1 mol / L.

4. The preparation method according to claim 1, characterized in that, The concentrations of the NaNO3 solution, NaF solution, and NaCl solution are all 5-8 mmol / L.

5. The preparation method according to claim 1, characterized in that, During the soaking treatment, the volume ratio of the silica nanofiber aerogel carrier to the mixed solution of zinc nitrate and cobalt nitrate, NaNO3 solution, NaF solution, and NaCl solution was 1:1; the soaking time was 24 hours.

6. The preparation method according to claim 1, characterized in that, The specific parameters for the low-temperature calcination include: oxygen concentration of 1-4 vol%, microwave power of 1500-3000 W, calcination temperature of 250-400℃, and calcination time of 2 h.

7. A high-performance desulfurization-regeneration coal gas desulfurizer prepared by the preparation method according to any one of claims 1-6.

8. A method for regenerating a high-desulfurization-regeneration performance coal gas desulfurizer as described in claim 7, characterized in that, Includes the following steps: Using a mixed gas with an oxygen concentration of 2 vol%, at a temperature of 450 °C for 2000 h... -1 The high-performance desulfurization-regeneration coal gas desulfurizer after desulfurization reaction is regenerated at a space velocity of 0.5 to obtain the regenerated coal gas desulfurizer.

9. The regeneration method as described in claim 8, characterized in that, The specific operation of the desulfurization reaction is as follows: A high-performance desulfurization-regeneration coal gas desulfurizer is placed in a fixed-bed reactor at a reaction time of 2000 h⁻¹. -1 Gas is introduced at air velocity and desulfurization reaction is carried out at 500℃.

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